JPH10188343A - Optical disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the optical disk capable of securing mechanical strength without changing its reference thickness even when a substrate is reduced in thickness. SOLUTION: This magneto-optical disk 1 is composed of the substrate 11 having a 1st thickness thinner than the reference thickness to become a standardized substrate thickness, a recording layer 12 to be layered on the substrate 11, a protective layer 13 to be layered on the recording layer 12 and a spacer 14 having a 2nd thickness to be layered on the protective layer 13, and the 1st thickness and the 2nd thickness make the reference thickness. By this constitution, the mechanical strength of the magneto-optical disk 1 can be secured without changing the reference thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical disk such as an optical disk and a magneto-optical disk used for recording an information signal.

[0002]

2. Description of the Related Art Hitherto, optical disks such as optical disks and magneto-optical disks have been used for storing data in computers or recording audio or video information.
This optical disc has a signal recording surface formed on a circular substrate formed of, for example, a transparent resin material.

For example, as shown in FIG. 9, a magneto-optical disk 101 on which an information signal can be written includes a substrate 102 formed in a circular shape using a transparent resin material such as polycarbonate, and a substrate 102 formed on the substrate 102. It is composed of a recording layer 103 formed of a magnetic film and a protective film 104 laminated on the recording layer 103. The magneto-optical disk 101 is formed such that the thickness t _{0 of the} substrate 102 is equal to a reference thickness defined by a standard. For example, the substrate thickness t ₀ is 1.2 mm.

Some magneto-optical disks are constructed by laminating the magneto-optical disk 101. As shown in FIG. 10, the magneto-optical disk formed by this bonding includes a first signal recording medium unit 106 and a second signal recording medium unit 107 each including a substrate 102, a recording layer 103, and a protective layer 104. Have been. The magneto-optical disk 105 is formed by bonding the upper surfaces 108 of the protective layers 104 and 104 together.

[0005] When mounted on an optical disk recording and / or reproducing apparatus, the magneto-optical disks 101 and 105 have hubs (not shown) mounted on rotary drive means provided in the optical disk recording and / or reproducing apparatus. The part is formed integrally with the substrate 102. The hub portion is designed based on the reference thickness so that the rotation driving means can appropriately mount the magneto-optical disks 101 and 105.

Here, the magneto-optical disks 101 and 105
This enables high-density recording of information signals by reducing the thickness t ₀ of the substrate 102.

[0007]

However, if the thickness t ₀ of the substrate 102 is changed, the substrate thickness becomes different from the reference thickness, so that the mounting position of the hub with respect to the rotation driving means changes. And magneto-optical disks 101 and 10
5 will not be properly mounted on this rotary drive means.

Further, when the thickness t ₀ of the substrate 102 is reduced, the mechanical strength is reduced, and, for example, during recording or reproduction, the magneto-optical disks 101 and 105 are wobbled or skewed. If recording or reproduction is performed in a state where the surface shake or skew has occurred, there arises a problem that information signals written or read to or from the magneto-optical disks 101 and 105 are deteriorated.

Further, if the thickness t ₀ of the substrate 102 is reduced, the magneto-optical disk
It becomes impossible to secure the strength against the impact when the rotation drive means is attached to or detached from the rotation drive unit 105.

Accordingly, the present invention has been made in view of the above circumstances, and has as its object to provide an optical disk which can secure mechanical strength without being different from a reference thickness even when a substrate thickness is reduced. I do.

[0011]

In order to solve the above-mentioned problems, an optical disk according to the present invention has a transparent substrate having a first thickness smaller than a reference thickness which is a thickness of a transparent substrate defined by a standard. And a recording layer laminated on the transparent substrate, and a reinforcing layer laminated on the recording layer on the side opposite to the transparent substrate, so that the first thickness and the second thickness form a reference thickness. I do.

With this configuration, the optical disk is provided with the reinforcing layer without changing the reference thickness, and secures mechanical strength.

An optical disc according to the present invention is formed by laminating two transparent substrates having a first thickness smaller than a standard thickness, which is a thickness of a transparent substrate defined by a standard, on each transparent substrate. Recording layer, and a reinforcing layer having a second thickness disposed between the recording layers, so that a half of the second thickness and the first thickness form a reference thickness.

With such a configuration, the optical disk is provided with the reinforcing layer without changing the reference thickness, and secures mechanical strength.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A magneto-optical disk according to an embodiment of the present invention will be described in detail with reference to the drawings.

First, the first embodiment is a magneto-optical disk capable of recording information signals by forming a recording layer with a magnetic film. This magneto-optical disk has a spacer as a reinforcing layer and is formed in a disk shape with a diameter of 5.25 inches and a thickness of approximately 1.2 mm.

As shown in FIG. 1, the magneto-optical disk 1 has a recording area 2 in which an information signal is recorded, and is located at an inner periphery of the recording area 2 to record information such as a sector length and a modulation method. Control track 3 and recording area 2
And a control track 4 and a control track 5 on which information such as recording and erasing conditions is recorded.

The control tracks 3, 4, 5 and the recording area 2 have a reference thickness of 1.2 m as shown in FIG.
m, a substrate 11 having a first thickness less than
It comprises a recording layer 12 laminated thereon, a protective film 13 laminated on the recording layer 12, and a spacer 14 laminated on the protective film 13 with a second thickness. The magneto-optical disk 1 forms the reference thickness of 1.2 mm with the first thickness and the second thickness.

The substrate 11 is formed of a transparent resin material such as polycarbonate so as to have a thickness of, for example, 0.6 mm.

The recording layer 12 is formed of a magnetic film, which enables information signals to be recorded. For example, when an information signal is recorded, the information signal is recorded on the recording layer 12 by irradiating a laser beam adjusted to a recording laser power and changing the direction of magnetization by a magnetic head.

The protective layer 13 is formed of a UV resin. The spacer 14 is formed of a transparent resin material such as polycarbonate, for example, like the substrate 11.

As shown in FIG. 1, when the magneto-optical disk 1 is loaded on an optical disk recording and / or reproducing apparatus, it is mounted on disk rotation driving means provided in the optical disk recording and / or reproducing apparatus. The hub portion 21 is formed integrally with the substrate 11. This hub 21
As shown in FIG. 3, a metal part 22 is formed in a substantially thin ring shape using, for example, a magnetic metal, and a metal holding part 23 is formed to hold the metal part 22.

The metal holding portion 23 is provided with a substantially ring-shaped mounting portion 24 adapted to the outer shape of the metal portion 22 and is integrally formed with the mounting portion 24 so that the metal portion 22 is sandwiched at its tip. Holding portions 25 and 26 formed so as to form
6 and a shaft insertion portion 27 in which a center shaft insertion hole of the disk rotation driving means is formed. With this configuration, the magnet provided in the disk rotation drive unit is joined to the metal part 22, the center axis is inserted into the shaft insertion portion 27, and the magneto-optical disk 1 is securely inserted into the disk rotation drive unit. Be attached.

The magneto-optical disk 1 constructed as described above
As shown in FIG. 4, a disk cartridge 3 composed of a substantially rectangular and thin box-shaped cartridge body 31 and the like.
2 so as to be rotatable. The disk cartridge 32 has a magnetic head entry opening 33 that is opened so that a magnetic head of an optical disk recording and / or reproducing apparatus can access a recording area 2 and the like of the magneto-optical disk 1 housed in the cartridge body 31. The disk rotation driving means entrance opening 34 opened so that the disk rotation driving means can enter the hub 21 of the magneto-optical disk 1, the magnetic head entrance opening 33 and the disk rotation driving means entrance opening 34 are closed. Shutter 3 slidably supported by the cartridge body 31 so that
5, an identifier hole 36 for identifying information or the like of the disk cartridge 32, and a positioning hole 37 formed for positioning when inserted into an optical disk recording and / or reproducing apparatus.

The magneto-optical disk 1 is housed in the disk cartridge 32 to prevent dust or the like from adhering to the signal recording surface. The magneto-optical disk 1 is loaded into an optical disk recording and / or reproducing apparatus (not shown) at the time of recording or reproduction, and is mounted on the disk rotation driving means as described above.

For example, since the magneto-optical disk 1 is provided with the spacers 14 so as to maintain the reference thickness, the hub 21 can be securely mounted even by using the conventional disk rotation driving means. Further, since the magneto-optical disk 1 is provided with the spacer 14, it is possible to secure the strength against the impact around the hub portion 21 when the disk rotation driving means is attached or detached.

This magneto-optical disk 1 is mounted on the above-described disk rotation drive means, and records or reproduces information signals. At this time, the magneto-optical disk 1 is
4, the rotation is performed without causing surface shake and skew. Thus, the deterioration of the information signal recorded or reproduced on the magneto-optical disk 1 is reduced.

That is, the magneto-optical disk 1 is
Since the mechanical strength can still be secured by reducing the thickness of the information signal, it is possible to record information signals with little deterioration at high density.

In the magneto-optical disk 1, since the thickness of the substrate 11 is reduced, the effects of spherical aberration, coma, astigmatism, etc. can be reduced. As a result, the margin for these aberrations is increased, so that the optical disc recording and / or reproducing apparatus is designed with a margin.

Since the thickness of the substrate 11 of the magneto-optical disk 1 can be reduced, the distance from the objective lens of the optical disk recording and / or reproducing apparatus, that is, the working distance can be increased. Further, the reduction in the thickness of the substrate 11 is advantageous when the numerical aperture of the objective lens is increased.

Next, a second embodiment will be described. In the second embodiment, a spacer is laminated on the upper surface of the recording layer,
This is a magneto-optical disk formed in a disk shape with a diameter of 5.25 inches and a thickness of approximately 1.2 mm.

As shown in FIG. 5, a recording area 2 and the like of the magneto-optical disk 1 have a substrate 11 having a first thickness smaller than a reference thickness of 1.2 mm and a recording layer laminated on the substrate 11. It comprises a layer 12 and a spacer 41 laminated on the recording layer 12 with a second thickness. The magneto-optical disk 1 is configured such that the first thickness and the second thickness form a reference thickness of 1.2 mm.

Here, for example, the thickness of the substrate 11 is 0.6
mm. The spacer 41 is formed of a transparent resin material such as polycarbonate.

The magneto-optical disk 1 is loaded into an optical disk recording and / or reproducing apparatus while being stored in the disk cartridge 32, as in the first embodiment.

The magneto-optical disk 1 constructed as described above
Is provided with the spacer 41 so as to maintain the reference thickness.
1 can be securely mounted. In addition, since the magneto-optical disk 1 includes the spacer 41, the hub 21
It is possible to secure the strength against the impact when the disk rotation driving means is attached to and detached from the periphery.

Further, the magneto-optical disk 1 has a spacer 4
1 so that it can be rotated without causing surface shake and skew. Thus, the deterioration of the information signal recorded or reproduced on the magneto-optical disk 1 is reduced.

That is, since the magneto-optical disk 1 is provided with the spacers 41, the thickness of the substrate 11 can be reduced and the mechanical strength can still be ensured. It becomes possible to record.

The magneto-optical disk 1 may have a protective film made of UV resin or the like instead of the spacer 41.

A third embodiment to be described next is a magneto-optical disk having a signal recording medium portion on both sides by bonding the magneto-optical disks shown in the first embodiment. That is, this magneto-optical disk has a diameter of 5.25 inches and a thickness of 2.4.
mm.

As shown in FIG. 6, the magneto-optical disk has a recording area or the like as described above, a substrate 11 having a first thickness, a recording layer 12 laminated on the substrate 11, Protective layer 13 having a second thickness on layer 12
And a first signal recording medium section 46 and a second signal recording medium section 47 each including a spacer 14 laminated on the protective layer 13 with a second thickness. Thus, the magneto-optical disk 48 has a thickness of 2.4 mm, which is twice the reference thickness.

The first signal recording medium section 46 and the second signal recording medium section 47 are formed so that the spacers 14 are disposed between the recording layers 12. That is, the magneto-optical disk 48 is formed by bonding the upper surfaces 49 of the spacers 14 to each other.

This magneto-optical disk 48 is loaded into an optical disk recording and / or reproducing apparatus while being stored in the disk cartridge 32, as in the first embodiment.

The magneto-optical disk 48 is mounted on the substrate 1
The hub 21 integrated with the first signal recording medium unit 4
6 and the second signal recording medium unit 47 side. The disc cartridge 32 has an identifier hole 3
In addition to 6, a second shaft hole is formed. This allows
Information on both signal recording surfaces can be recorded on the disc cartridge 32.

The magneto-optical disk 48 thus configured
Since the hubs 21 are provided with the spacers 14 so as to maintain the reference thickness, the hub portion 21 can be securely mounted even by using the conventional disk rotation driving means. Further, since the magneto-optical disk 48 is provided with the spacers 14, 14, it is possible to ensure the strength against the impact around the hub portion 21 when the disk rotation driving means is attached or detached.

Further, since the magneto-optical disk 48 is provided with the spacers 14, 14, it is rotated without causing surface wobble and skew. Thus, the deterioration of the information signal recorded or reproduced on the magneto-optical disk 48 is reduced.

That is, the magneto-optical disk 48 having the spacers 14, 14 can reduce the thickness of the substrates 11, 11 and still increase the mechanical strength. It becomes possible to record with.

The fourth embodiment to be described next is a magneto-optical disk formed by bonding the magneto-optical disks 1 described in the second embodiment. This magneto-optical disk is formed to have a diameter of 5.25 inches and a thickness of 2.4 mm.

As shown in FIG. 7, the recording area of the magneto-optical disk includes a substrate 11 having a first thickness, a recording layer 12 laminated on the substrate 11, and a second layer 11 on the recording layer 12.
Signal recording medium unit 51 and second signal recording medium unit 52 each including a spacer 41 having a thickness of
Is formed. Thereby, the magneto-optical disk 5
3 has a thickness of 2.4 mm, which is twice the reference thickness.

The first signal recording medium section 51 and the second signal recording medium section 52 are bonded together so that spacers 41 are disposed between the recording layers 12. . That is, the magneto-optical disk 53 is
The upper surfaces 54 are bonded together.

The magneto-optical disk 53 is the third type described above.
Is stored in the same disk cartridge 32 as in the embodiment. The magneto-optical disk 53 has the hub portion 21 formed on the first signal recording surface 51 side and the second signal recording surface 52 side similarly to the third embodiment.

Then, the magneto-optical disk 53 is loaded into an optical disk recording and / or reproducing apparatus while being stored in the disk cartridge 32.

The magneto-optical disk 53 thus configured
Since the hub is provided with the spacers 41 so that the reference thickness does not change, the hub portion can be securely mounted even by using the conventional disk rotation driving means. Further, since the magneto-optical disk 53 is provided with the spacers 41, 41, it is possible to ensure the strength against the impact around the hub portion 21 when the disk rotation driving means is attached or detached.

Further, since the magneto-optical disk 53 is provided with the spacers 41, 41, it is rotated without causing surface wobble and skew. As a result, deterioration of the information signal recorded or reproduced on the magneto-optical disk 53 is reduced.

That is, in the magneto-optical disk 53 provided with the spacers 41, 41, the mechanical strength can be increased while the thickness of the substrates 11, 11 is reduced. It becomes possible to record.

It should be noted that the magneto-optical disk 53 is
A protective film can be formed instead of 1.

The fifth embodiment to be described below is a magneto-optical disk formed with a recording layer on both sides of one spacer and formed in a disk shape. As shown in FIG. 8, the magneto-optical disk has two substrates 61, 61 having a first thickness smaller than a standard thickness defined by a standard, and a recording layer laminated on each of the substrates 61, 61. And a spacer 63 disposed between the recording layers 62 and 62 and formed as a reinforcing layer having a second thickness. Here, the magneto-optical disk 64 is formed such that the thickness is half of the second thickness and the first thickness is a reference thickness. Here, the reference thickness is, for example, 1.2 mm. Therefore, the magneto-optical disk 64 is formed so as to have an overall thickness of 2.4 mm.

The magneto-optical disk 64 has the hub portions 21 described in the third embodiment on both sides, and the hub portions 21 are integrally formed on the substrates 11, 11. The magneto-optical disk 64 is rotatably housed in the disk cartridge 32 as described in the third embodiment. Since the magneto-optical disk 64 is housed in the disk cartridge 32, it is possible to prevent dust or the like from adhering to the signal recording surface.

Then, the magneto-optical disk 64 is loaded into an optical disk recording and / or reproducing apparatus while being stored in the disk cartridge 32.

The magneto-optical disk 64 thus configured
Since the spacers 63 are provided so as to maintain the double reference thickness, the hub portion 21 can be securely mounted even by using the conventional disk rotation driving means. Further, since the magneto-optical disk 64 is provided with the spacer 63, it is possible to secure the strength against the impact around the hub portion 21 at the time of attaching and detaching the disk rotation driving means.

Further, since the magneto-optical disk 64 is provided with the spacer 63, it is rotated without causing surface wobble and skew. Thereby, the magneto-optical disk 6
The deterioration of the information signal recorded or reproduced for No. 4 is reduced.

That is, since the magneto-optical disk 64 provided with the spacers 63 can secure the mechanical strength by reducing the thickness of the substrates 11, 11, information signals with little deterioration are recorded at high density. It becomes possible.

The magneto-optical disk is not limited to the use of polycarbonate for the reinforcing portion, but may be made of a transparent material having excellent mechanical properties. As a result, the magneto-optical disk has a further increased mechanical strength.

The optical disk according to the present invention can also be applied to an optical disk having a recording section formed by pits.

[0064]

The optical disk according to the present invention has a reinforcing layer on the recording layer opposite to the transparent substrate, which does not change the reference thickness. Strength can be secured.

Further, since the optical disk has a reinforcing layer, the thickness of the transparent substrate can be reduced so that the mechanical strength can be secured, and an information signal with little deterioration can be recorded at a high density. Will be possible.

[Brief description of the drawings]

FIG. 1 is a plan view of a magneto-optical disk according to an embodiment of the present invention.

FIG. 2 is a sectional view of the magneto-optical disk provided with a protective film and a spacer.

FIG. 3 is a sectional view showing a hub portion of the magneto-optical disk.

FIG. 4 is a perspective view showing the magneto-optical disk stored in a disk cartridge.

FIG. 5 is a sectional view of the magneto-optical disk having a spacer.

FIG. 6 is a cross-sectional view showing a magneto-optical disk provided with a protective film and a spacer and bonded together.

FIG. 7 is a cross-sectional view showing a magneto-optical disk provided with spacers and formed by bonding.

FIG. 8 is a sectional view showing a magneto-optical disk in which recording layers are formed on both surfaces of one spacer.

FIG. 9 is a sectional view of a conventional magneto-optical disk.

FIG. 10 is a sectional view of a conventional bonded magneto-optical disk.

[Explanation of symbols]

1 magneto-optical disk, 11 substrate, 12 recording layer, 13
Protective layer, 14 spacer, 61 substrate, 62 recording layer, 63 spacer

Claims (7)

[Claims] 1. A transparent substrate having a first thickness smaller than a reference thickness that is a thickness of a transparent substrate defined by a standard, a recording layer laminated on the transparent substrate, and An optical disk comprising: a reinforcing layer laminated on a side opposite to a transparent substrate; wherein the first thickness and the second thickness form the reference thickness. 2. The optical disk according to claim 1, wherein the reinforcing layer is a spacer. 3. The optical disk according to claim 1, wherein the reference thickness is approximately 1.2 mm. 4. The optical disk according to claim 1, wherein the substrate is a magneto-optical disk having a substrate diameter of 5.25 inches. 5. The optical disk according to claim 1, wherein the reinforcing layer is a protective film. 6. The apparatus according to claim 1, further comprising two transparent substrates, two recording layers, and two reinforcing layers.
2. The optical disc according to claim 1, wherein two reinforcing layers are provided by bonding. 7. A transparent substrate having a first thickness smaller than a reference thickness, which is a thickness of a transparent substrate defined by a standard, a recording layer laminated on each of the transparent substrates, An optical disk, comprising: a reinforcing layer having a second thickness disposed between layers, wherein a half of the second thickness and the first thickness form the reference thickness.